ARC-DISCHARGE AT ELECTRICAL CONTACTS

Arc discharge at switching contacts is one of the key phenomena, becau se it strongly affects material wear/transfer, contact resistance and electromagnetic interference (EMI). The are discharge is classified in to various types from the viewpoint of its sustaining mechanism and vo ltage waveform. They are mainly steady are, showering are and initial are. Furthermore, a steady are consists of two stages named metallic p hase are and gaseous phase are. In the metallic phase are, metal ions from the electrodes mainly sustain the are. On the other hand, gas ion s from the surrounding atmosphere play an important role in the gaseou s phase. Each phase are has different influence on contact performance and EMI. The purpose of this paper is to review the are discharges at light duty electrical contacts, and to survey the effects of are disc harges on material transfer and EMI.